2101510101 has 4 divisors (see below), whose sum is σ = 2802013472. Its totient is φ = 1401006732.

The previous prime is 2101510091. The next prime is 2101510139. The reversal of 2101510101 is 1010151012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 2101510101 - 2⁹ = 2101509589 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2101510171) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 350251681 + ... + 350251686.

It is an arithmetic number, because the mean of its divisors is an integer number (700503368).

Almost surely, 2^2101510101 is an apocalyptic number.

It is an amenable number.

2101510101 is a deficient number, since it is larger than the sum of its proper divisors (700503371).

2101510101 is an equidigital number, since it uses as much as digits as its factorization.

2101510101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 700503370.

The product of its (nonzero) digits is 10, while the sum is 12.

The square root of 2101510101 is about 45842.2305412815. The cubic root of 2101510101 is about 1280.8860444371.

Adding to 2101510101 its reverse (1010151012), we get a palindrome (3111661113).

The spelling of 2101510101 in words is "two billion, one hundred one million, five hundred ten thousand, one hundred one".